1//===-- FileCache.cpp -------------------------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "lldb/Host/FileCache.h"
10
11#include "lldb/Host/File.h"
12#include "lldb/Host/FileSystem.h"
13
14using namespace lldb;
15using namespace lldb_private;
16
17FileCache *FileCache::m_instance = nullptr;
18
19FileCache &FileCache::GetInstance() {
20  if (m_instance == nullptr)
21    m_instance = new FileCache();
22
23  return *m_instance;
24}
25
26lldb::user_id_t FileCache::OpenFile(const FileSpec &file_spec,
27                                    File::OpenOptions flags, uint32_t mode,
28                                    Status &error) {
29  if (!file_spec) {
30    error.SetErrorString("empty path");
31    return UINT64_MAX;
32  }
33  auto file = FileSystem::Instance().Open(file_spec, flags, mode);
34  if (!file) {
35    error = file.takeError();
36    return UINT64_MAX;
37  }
38  lldb::user_id_t fd = file.get()->GetDescriptor();
39  m_cache[fd] = std::move(file.get());
40  return fd;
41}
42
43bool FileCache::CloseFile(lldb::user_id_t fd, Status &error) {
44  if (fd == UINT64_MAX) {
45    error.SetErrorString("invalid file descriptor");
46    return false;
47  }
48  FDToFileMap::iterator pos = m_cache.find(fd);
49  if (pos == m_cache.end()) {
50    error.SetErrorStringWithFormat("invalid host file descriptor %" PRIu64, fd);
51    return false;
52  }
53  FileUP &file_up = pos->second;
54  if (!file_up) {
55    error.SetErrorString("invalid host backing file");
56    return false;
57  }
58  error = file_up->Close();
59  m_cache.erase(pos);
60  return error.Success();
61}
62
63uint64_t FileCache::WriteFile(lldb::user_id_t fd, uint64_t offset,
64                              const void *src, uint64_t src_len,
65                              Status &error) {
66  if (fd == UINT64_MAX) {
67    error.SetErrorString("invalid file descriptor");
68    return UINT64_MAX;
69  }
70  FDToFileMap::iterator pos = m_cache.find(fd);
71  if (pos == m_cache.end()) {
72    error.SetErrorStringWithFormat("invalid host file descriptor %" PRIu64, fd);
73    return false;
74  }
75  FileUP &file_up = pos->second;
76  if (!file_up) {
77    error.SetErrorString("invalid host backing file");
78    return UINT64_MAX;
79  }
80  if (static_cast<uint64_t>(file_up->SeekFromStart(offset, &error)) != offset ||
81      error.Fail())
82    return UINT64_MAX;
83  size_t bytes_written = src_len;
84  error = file_up->Write(src, bytes_written);
85  if (error.Fail())
86    return UINT64_MAX;
87  return bytes_written;
88}
89
90uint64_t FileCache::ReadFile(lldb::user_id_t fd, uint64_t offset, void *dst,
91                             uint64_t dst_len, Status &error) {
92  if (fd == UINT64_MAX) {
93    error.SetErrorString("invalid file descriptor");
94    return UINT64_MAX;
95  }
96  FDToFileMap::iterator pos = m_cache.find(fd);
97  if (pos == m_cache.end()) {
98    error.SetErrorStringWithFormat("invalid host file descriptor %" PRIu64, fd);
99    return false;
100  }
101  FileUP &file_up = pos->second;
102  if (!file_up) {
103    error.SetErrorString("invalid host backing file");
104    return UINT64_MAX;
105  }
106  if (static_cast<uint64_t>(file_up->SeekFromStart(offset, &error)) != offset ||
107      error.Fail())
108    return UINT64_MAX;
109  size_t bytes_read = dst_len;
110  error = file_up->Read(dst, bytes_read);
111  if (error.Fail())
112    return UINT64_MAX;
113  return bytes_read;
114}
115